Well You can still keep your old stats.
Just use the date trick then pull up "All Time" stats and click Ctrl+S to save to a csv file.
I saved two files, one with all the columns and one where I just kept sales, rebills, $$$ and ratio for easier viewing.
(or just do the date trick every time you wanna check old stats :D )
Would be nice if I could export my 256 sponsors into NS but then again I can probably remove a large bunch of those sponsors
